Epilepsy could be risk factor for developing Parkinson’s

Published: March 15 2022
Last updated: May 12 2023

Epilepsy and hearing loss are among some of the risk factors for developing Parkinson’s disease later in life, according to a new study in JAMA Neurology.

Dr Christina Simonet and colleagues aimed to investigate common risk factors for Parkinson’s disease and how early these can occur before a Parkinson’s disease diagnosis is made. The research wanted to focus on an ethnically diverse group of people from less affluent backgrounds.

The study used the electronic health records from GP practices in East London of over a million people between 1990 and 2018. They compared people with Parkinson’s disease stated in their medical record to those without. People with neurological diseases that get worse with time, such as dementia and multiple sclerosis (MS), were not included in the study.

The researchers found that people with Parkinson’s disease tended to be older and more often male, compared to the group without. Loss of hearing and epilepsy were found to be risk factors for Parkinson’s disease, which haven’t been well reported before.

According to the NHS website, Parkinson’s disease is thought to affect around one in every 500 people. The researchers found that people with epilepsy are 2.5 times more likely to be diagnosed with Parkinson’s disease than the general population. This means for every 500 people with epilepsy, two or three people will go on to have a diagnosis of Parkinson’s disease.

Consultant neurologist at the Royal Victoria Infirmary in Newcastle, Dr Rhys Thomas, said: “This is not the first time that epilepsy has been suggested to be a risk factor for Parkinson’s disease, but the size of the study makes this finding potentially important.

“There could be a few different reasons for this increased risk of being diagnosed with Parkinson’s disease in people with epilepsy. If you are already seeing a neurologist for something else, and you do have early signs of Parkinson’s disease, you are more likely to have it diagnosed correctly. Also, some epilepsy medicines can cause a tremor, which could be misdiagnosed as Parkinson’s disease (what is called parkinsonism) or it could prompt a doctor to investigate for Parkinson’s disease.

“Epilepsy is a term for a number of diseases, and some of them may be more likely to increase the risk of Parkinson’s disease than others, specifically vascular disease.”

Other risk factors included tremors, seen up to 10 years before the diagnosis of Parkinson’s disease, and memory problems, present up to five years before. Links were also found with high blood pressure, low blood pressure, constipation, depression and type 2 diabetes.

There is more information on this study on the JAMA Neurology website.